Research

Performance of vertical moisture barriers

(118K) ABSTRACT: Vertical moisture barriers are used to minimise the seasonal movement of pavements on expansive soil subgrades. This paper discusses the performance of two types of barriers – geomembrane and L/FA grout curtain– at two test sites in Victoria, Australia.

Application of moisture barriers for expansive soils

(194K) ABSTRACT: Vertical moisture barriers are used to minimise the differential movement of pavements on expansive soil subgrades. This paper discusses two types of barrier: (1) the geomembrane barrier, developed for alluvial expansive soils, and (2) the lime and fly ash grout curtain, for residual expansive soils.

Monitoring the Performance of Moisture Barriers

(505K) ABSTRACT: This paper looks at the new method of monitoring the effectiveness of vertical moisture barriers based on the ARRB Walking Profiler. It was found to be an accurate, relatively rapid and cost effective means of monitoring the performance of vertical moisture barriers, which are used alongside pavements to minimise the damaging effects of expansive soils.

Application of Newly Developed Stabilising Additives in the Rehabilitation of Existing Road Pavements (local roads with light to medium traffic)

(28K) ABSTRACT: In the last few years, stabilisation of pavement materials has become one of the most common methods of pavement rehabilitation. To this effect, pozzolans (such as lime and cement) have been used to enhance the engineering properties of the pavement materials. Also, ground granulated blast furnace slag (GGBFS or Slag), alkali activated slag (eg. Roadment) and Fly Ash (blended with lime or cement) are examples of “waste” products used as additives due to their pozzolanic properties. This paper summarises some of the latest research and field applications of these additives in Victoria.

Evaluation of Stabilised Marginal Pavement Materials Using Stabilised and Newly Developed Cementious Binders

(312K) ABSTRACT: This paper will present the findings of various research programs and laboratory tests on the effects of slow-setting cementitious stabilisation binders on marginal pavement materials. It will present the VicRoads evaluation of the slow-setting binder developed by Blue Circle Southern Cement, Alkali-Activated Slag (commercially known as “Roadment”). The information presented includes research work performed by a wide range of organisations, including private industry, state road authorities and local government. An overview of the need for and the development of these slow-setting binders will also be discussed. The conclusion will summarise the adverse effects of delays to compaction on materials stabilised with GP and GB cements and the advantage that slow-setting binders have when extended working time is desired.

Survey Results on Stabilisation methods and performance of local government roads in Australia

(1.8M) ABSTRACT: Local government roads constitute more than 80% of the 810,000km long road network in Australia. The combination of larger vehicle loads, increased traffic flows, ageing infrastructure and adverse environmental conditions has contributed to continual degradation of many Australian roads. This paper presents results of a survey undertaken to determine the state of the road stabilisation practice in various local governments (councils) throughout Australia. The survey covered pavement material types and thicknesses, methods of rehabilitation of degraded pavements, type and quantity of chemical additives used, modes and causes of pavement distress, and impediments to the widespread use of chemical stabilisation in local government roads. Clayey gravel or gravel, and crushed igneous rocks are commonly used as pavement materials, and cementitious binders are the main stabilising agents. Within states, there were variations in the use of pavement materials, modes of distress of pavements and their rehabilitation, and uses of chemical stabilisers. Cracking appeared to be the dominant mode of distress in chemically stabilised pavements. Shrinkage of pavement materials is considered to be a dominant cause of pavement cracking.